Append --force-update for specific helm versions. (#1494)

* Parse and process helm version using github.com/Masterminds/semver/v3.

* Add --force-update only when Helm version >= 3.3.2, < 3.3.4.

See: https://github.com/helm/helm/pull/8777.

* Add test cases.

pkg/helmexec/exec.go

@@ -6,11 +6,11 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"regexp"
 	"strconv"
 	"strings"
 	"sync"
 
+	"github.com/Masterminds/semver/v3"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 )
@@ -22,7 +22,7 @@ type decryptedSecret struct {
 
 type execer struct {
 	helmBinary           string
-	version              Version
+	version              semver.Version
 	runner               Runner
 	logger               *zap.SugaredLogger
 	kubeContext          string
@@ -48,51 +48,33 @@ func NewLogger(writer io.Writer, logLevel string) *zap.SugaredLogger {
 	return zap.New(core).Sugar()
 }
 
-// versionRegex matches versions like v1.1.1 and v1.1
-var versionRegex = regexp.MustCompile("v(?P<major>\\d+)\\.(?P<minor>\\d+)(?:\\.(?P<patch>\\d+))?")
-
-func parseHelmVersion(versionStr string) (Version, error) {
+func parseHelmVersion(versionStr string) (semver.Version, error) {
 	if len(versionStr) == 0 {
-		return Version{}, nil
+		return semver.Version{}, nil
 	}
 
-	matches := versionRegex.FindStringSubmatch(versionStr)
-	if len(matches) == 0 {
-		return Version{}, fmt.Errorf("error parsing helm verion '%s'", versionStr)
-	}
-	result := make(map[string]string)
-	for i, name := range versionRegex.SubexpNames() {
-		result[name] = matches[i]
-	}
+	versionStr = strings.TrimLeft(versionStr, "Client: ")
+	versionStr = strings.TrimRight(versionStr, "\n")
 
-	// We ignore errors because regex matches only integers
-	// If any of the parts does not exist - default "0" will be used
-	major, _ := strconv.Atoi(result["major"])
-	minor, _ := strconv.Atoi(result["minor"])
-	patch, _ := strconv.Atoi(result["patch"])
+	ver, err := semver.NewVersion(versionStr)
+	if err != nil {
+		return semver.Version{}, fmt.Errorf("error parsing helm verion '%s'", versionStr)
+	}
 
 	// Support explicit helm3 opt-in via environment variable
-	if os.Getenv("HELMFILE_HELM3") != "" && major < 3 {
-		return Version{
-			Major: 3,
-			Minor: 0,
-			Patch: 0,
-		}, nil
+	if os.Getenv("HELMFILE_HELM3") != "" && ver.Major() < 3 {
+		return *semver.MustParse("v3.0.0"), nil
 	}
 
-	return Version{
-		Major: major,
-		Minor: minor,
-		Patch: patch,
-	}, nil
+	return *ver, nil
 }
 
-func getHelmVersion(helmBinary string, runner Runner) (Version, error) {
+func getHelmVersion(helmBinary string, runner Runner) (semver.Version, error) {
 
 	// Autodetect from `helm verison`
 	bytes, err := runner.Execute(helmBinary, []string{"version", "--client", "--short"}, nil)
 	if err != nil {
-		return Version{}, fmt.Errorf("error determining helm version: %w", err)
+		return semver.Version{}, fmt.Errorf("error determining helm version: %w", err)
 	}
 
 	return parseHelmVersion(string(bytes))
@@ -130,9 +112,16 @@ func (helm *execer) AddRepo(name, repository, cafile, certfile, keyfile, usernam
 		return fmt.Errorf("empty field name")
 	}
 	args = append(args, "repo", "add", name, repository)
-	if helm.IsHelm3() && helm.IsVersionAtLeast(3, 3, 2) {
-		args = append(args, "--force-update")
+
+	// See https://github.com/helm/helm/pull/8777
+	if cons, err := semver.NewConstraint(">= 3.3.2, < 3.3.4"); err == nil {
+		if cons.Check(&helm.version) {
+			args = append(args, "--force-update")
+		}
+	} else {
+		panic(err)
 	}
+
 	if certfile != "" && keyfile != "" {
 		args = append(args, "--cert-file", certfile, "--key-file", keyfile)
 	}
@@ -394,13 +383,18 @@ func (helm *execer) write(out []byte) {
 }
 
 func (helm *execer) IsHelm3() bool {
-	return helm.version.Major == 3
+	return helm.version.Major() == 3
 }
 
 func (helm *execer) GetVersion() Version {
-	return helm.version
+	return Version{
+		Major: int(helm.version.Major()),
+		Minor: int(helm.version.Minor()),
+		Patch: int(helm.version.Patch()),
+	}
 }
 
-func (helm *execer) IsVersionAtLeast(major int, minor int, patch int) bool {
-	return helm.version.Major >= major && helm.version.Minor >= minor && helm.version.Patch >= patch
+func (helm *execer) IsVersionAtLeast(versionStr string) bool {
+	ver := semver.MustParse(versionStr)
+	return helm.version.Equal(ver) || helm.version.GreaterThan(ver)
 }